Vertical restrictive strabismus associated with proptosis: Similar clinical signs, different etiopathogenetic causes. A report of three patients.

Although proptosis and acquired vertical restrictive strabismus are most commonly associated with thyroid associated orbitopathy (TAO), they can also be a manifestation of many other conditions and the differential diagnosis can be particularly challenging. The three reported cases presented indeed with similar clinical features but had three distinct underlying orbital etiologies, two of which were extremely uncommon.